Datasheet

LTC3600
13
3600fc
In most applications, the input capacitor is merely required
to supply high frequency bypassing, since the impedance to
the supply is very low. A 22µF ceramic capacitor is usually
enough for these conditions. Place this input capacitor as
close to V
IN
pin as possible.
Inductor Selection
Given the desired input and output voltages, the inductor
value and operating frequency determine the ripple current:
∆I
L
SW
=
V
OUT
f • L






1−
V
OUT
V
IN






Lower ripple current reduces core losses in the inductor,
ESR losses in the output capacitors, and output voltage
ripple. Highest efficiency operation is obtained at low
frequency with small ripple current. However, achieving
this requires a large inductor. There is a trade-off between
component size, efficiency and operating frequency.
A reasonable starting point is to choose a ripple current
that is about 40% of I
OUT(MAX)
. Note that the largest ripple
current occurs at the highest V
IN
. To guarantee that ripple
current does not exceed a specified maximum, the induc-
tance should be chosen according to:
L =
V
OUT
• ∆I
L(MAX)






1−
V
OUT
V
IN(MAX)






SW
f
applicaTions inForMaTion
Table 1. Inductor Selection Table
INDUCTOR
INDUCTANCE
(µH)
DCR
(mΩ)
MAX CURRENT
(A)
DIMENSIONS
(mm)
HEIGHT
(mm) MANUFACTURER
IHLP-1616BZ-11 Series 1.0
2.2
4.7
24
61
95
4.5
3.25
1.7
4.3 × 4.7
4.3 × 4.7
4.3 × 4.7
2
2
2
Vishay
www.vishay.com
IHLP-2020BZ-01 Series 1
2.2
3.3
4.7
5.6
6.8
18.9
45.6
79.2
108
113
139
7
4.2
3.3
2.8
2.5
2.4
5.4 × 5.7
5.4 × 5.7
5.4 × 5.7
5.4 × 5.7
5.4 × 5.7
5.4 × 5.7
2
2
2
2
2
2
FDV0620 Series 1
2.2
3.3
4.7
18
37
51
68
5.7
4
3.2
2.8
6.7 × 7.4
6.7 × 7.4
6.7 × 7.4
6.7 × 7.4
2
2
2
2
Toko
www.toko.com
MPLC0525L Series 1
1.5
2.2
16
24
40
6.4
5.2
4.1
6.2 × 5.4
6.2 × 5.4
6.2 × 5.4
2.5
2.5
2.5
NEC/Tokin
www.nec-tokin.com
HCP0703 Series 1
1.5
2.2
3.3
4.7
6.8
8.2
9
14
18
28
37
54
64
11
9
8
6
5.5
4.5
4
7 × 7.3
7 × 7.3
7 × 7.3
7 × 7.3
7 × 7.3
7 × 7.3
7 × 7.3
3
3
3
3
3
3
3
Cooper Bussmann
www.cooperbussmann.com
RLF7030 Series 1
1.5
2.2
3.3
4.7
6.8
8.8
9.6
12
20
31
45
6.4
6.1
5.4
4.1
3.4
2.8
6.9 × 7.3
6.9 × 7.3
6.9 × 7.3
6.9 × 7.3
6.9 × 7.3
6.9 × 7.3
3.2
3.2
3.2
3.2
3.2
3.2
TDK
www.tdk.com
WE-TPC 4828 Series 1.2
1.8
2.2
2.7
3.3
3.9
4.7
17
20
23
27
30
47
52
3.1
2.7
2.5
2.35
2.15
1.72
1.55
4.8 × 4.8
4.8 × 4.8
4.8 × 4.8
4.8 × 4.8
4.8 × 4.8
4.8 × 4.8
4.8 × 4.8
2.8
2.8
2.8
2.8
2.8
2.8
2.8
Würth Elektronik
www.we-online.com